Tire inflation system having a rotary coupling

ABSTRACT

A tire inflation system having a rotary coupling. The rotary coupling may have a mounting member and a rotating member. The rotating member may be rotatably coupled to the mounting member and may have a rotating member passage that may fluidly connect a first conduit to a second conduit that may be fluidly connected to the tire.

TECHNICAL FIELD

This patent application relates to a tire inflation system that has arotary coupling.

BACKGROUND

A tire inflation system is disclosed in U.S. Pat. No. 7,931,061.

SUMMARY

In at least one embodiment, a tire inflation system is provided. Thetire inflation system may include a first conduit, an axle housing, anda rotary coupling. The first conduit may supply a pressurized gas forinflating a tire. The rotary coupling may have a mounting member and arotating member. The mounting member may be disposed proximate the axlehousing and the first conduit. The rotating member may be rotatablycoupled to the mounting member. The rotating member may have a rotatingmember passage that may fluidly connect the first conduit to a secondconduit that may be fluidly connected to the tire.

In at least one embodiment, a tire inflation system is provided. Thetire inflation system may include a first conduit, an axle housing, anda rotary coupling. The first conduit may supply a pressurized gas forinflating a tire. The rotary coupling may include a first mountingmember, a block, and a rotating member. The first mounting member may bedisposed proximate the axle housing and the first conduit. The block maybe disposed proximate the axle housing and the first mounting member.The block may include a block passage that may be fluidly connected tothe first conduit. The rotating member may rotate with respect to themounting member. The rotating member may have a rotating member passagethat may fluidly connect the block passage to a second conduit. Thesecond conduit may be fluidly connected to the tire.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of an exemplary axle assembly having a tireinflation system.

FIGS. 2 and 3 are section views of exemplary rotary couplings that maybe provided with the axle assembly.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Referring to FIG. 1, a portion of an exemplary axle assembly 10 isshown. The axle assembly 10 may be provided with a motor vehicle like atruck, bus, farm equipment, military transport or weaponry vehicle, orcargo loading equipment for land, air, or marine vessels.

The axle assembly 10 may be configured as a drive axle that may receivetorque from a power source, such as an internal combustion engine orelectric motor. Alternatively, the axle assembly 10 may be configured asa non-drive axle in one or more embodiments. The axle assembly 10 may ormay not be steerable. In a drive axle configuration, the axle assembly10 may include an axle housing 20, an axle shaft 22, a spindle 24, awheel end assembly 26, and a rotary coupling 28.

The axle housing 20 may receive various components of the axle assembly10. In addition, the axle housing 20 may facilitate mounting of the axleassembly 10 to the vehicle. The axle housing 20 may define a cavity thatmay receive at least a portion of the axle shaft 22. The axle housing 20may include the spindle 24.

The axle shaft 22 may provide torque to the wheel end assembly 26 topropel the vehicle. For instance, the axle shaft 22 may be connected ata first end to a vehicle drivetrain component, like a differential orinput shaft, and may be coupled to the wheel end assembly 26 at a secondend. In at least one embodiment, the axle shaft 22 may extend along andmay rotate about an axis 30. Alternatively, the axle shaft 22 may beconfigured for use with an independent suspension system and may havemultiple shaft segments and/or joints, such as constant-velocity joints,that may facilitate relative movement between the first end and thewheel end assembly 26. The axle shaft 22 may include an axle flange 32disposed at a distal end. The axle flange 32 may facilitate mounting ofthe wheel end assembly 26 to the axle shaft 22. In a non-drive axleconfiguration, the axle shaft 22 may be omitted.

The spindle 24 may be provided with or may be fixedly positioned withrespect to the axle assembly 10. The spindle 24 may generally extendalong but may not rotate about the axis 30. In a drive axleconfiguration, the spindle 24 may include a first end surface 40, asecond end surface 42, an internal surface 44, an external surface 46,and a hole 48. In a non-drive axle configuration, the internal surface44 and the hole 48 may be omitted. Moreover, in a steerable non-driveaxle configuration, the spindle 24 may be provided with or may befixedly positioned with respect to a steering knuckle rather than theaxle housing 20. The first end surface 40 may be disposed proximate ormay engage the axle housing 20. The second end surface 42 may bedisposed opposite the first end surface 40 and may be located near theaxle flange 32. The internal surface 44 may extend between the first endsurface 40 and the second end surface 42 and may at least partiallydefine the hole 48 through which the axle shaft 22 may extend. As such,the spindle 24 may be spaced apart from the axle shaft 22 to permit theaxle shaft 22 to rotate about the axis 30. The external surface 46 maybe disposed opposite the internal surface 44. The external surface 46 ofthe spindle 24 may support one or more wheel bearings that may rotatablysupport the wheel end assembly 26 as will be discussed in more detailbelow.

The wheel end assembly 26 may be rotatably coupled to the axle shaft 22.The wheel end assembly 26 may include a hub 50, a wheel end sealassembly 52, a brake subsystem 54, a wheel 56, and a tire 58.

The hub 50 may be rotatably disposed on the spindle 24. For instance,one or more wheel bearings may be mounted on spindle 24 and mayrotatably support the hub 50. In FIG. 1, a first wheel bearing 60 and asecond wheel bearing 62 are provided in a cavity 64 that is locatedbetween the spindle 24 and the hub 50. The first wheel bearing 60 may bedisposed inboard or further from the second end surface 42 than thesecond wheel bearing 62. As such, the hub 50 may be configured to rotateabout the axis 30. In a drive axle configuration, the axle flange 32 maybe coupled to the hub 50 with one or more fasteners 66. As such, the hub50 may rotate with the axle shaft 22. In a non-drive axle configuration,the hub 50 may not be coupled to an axle shaft 22 or axle flange 32.

The wheel end seal assembly 52 may be disposed between the spindle 24and the hub 50. The wheel end seal assembly 52 may inhibit contaminantsfrom entering the cavity 64 and may help retain lubricant in the cavity64. In at least one embodiment, the wheel end seal assembly 52 may befixedly disposed with respect to the hub 50 and may rotate about theaxis 30 and with respect to the spindle 24.

The brake subsystem 54 may be adapted to slow or inhibit rotation of atleast one associated wheel 56. For example, the brake subsystem 54 maybe configured as a friction brake, such as a drum brake or a disc brake.In FIG. 1, a portion of the brake subsystem 54 is shown with a drumbrake configuration. In a drum brake configuration, a brake drum 70 maybe fixedly disposed on the hub 50 with one or more fasteners 72, such aswheel lug studs. The brake drum 70 may extend continuously around brakeshoe assemblies (not shown) that may be configured to engage the brakedrum 70 to slow rotation of an associated wheel 56.

The wheel 56 may be fixedly disposed on the hub 50. For example, thewheel 56 may be mounted on the hub 50 via the fasteners 72. Morespecifically, the wheel 56 may have a wheel mounting flange 74 that mayhave a set of holes that may each receive a fastener 72. In at least oneembodiment, a fastener 72 may be hollow or have a through hole thatfacilitates the routing of pressurized gas through the fastener 72. Alug nut 76 may be threaded onto each fastener to secure the wheel 56 tothe fasteners 72 and the hub 50. The lug nut 76 may engage or may bedisposed proximate an outboard side 78 of the wheel mounting flange 74that faces way from the brake drum 70 or toward the axle flange 32. Thewheel 56 may be configured to support the tire 58. The tire 58 may be apneumatic tire that may be inflated with a pressurized gas orpressurized gas mixture.

A tire inflation system 80 may be associated with the wheel end assembly26. The tire inflation system 80 may be disposed on the vehicle and maybe configured to provide a pressurized gas or pressurized gas mixture toone or more tires 58. For clarity, the term “pressurized gas” may referto either a pressurized gas or a pressurized gas mixture. The tireinflation system 80 may include a control system that may monitor andcontrol the inflation of one or more tires 58, a pressurized gas source82, and a gas supply subsystem 84.

The pressurized gas source 82 may be configured to supply or store avolume of a pressurized gas or pressurized gas mixture, like air ornitrogen. For example, the pressurized gas source 82 may be a tankand/or a pump like a compressor. The pressurized gas source 82 may bedisposed on the vehicle and may provide a pressurized gas or pressurizedgas mixture at a pressure that is greater than or equal to a desiredinflation pressure of a tire 58. As such, the pressurized gas source 82may inflate a tire or maintain a desired tire pressure.

The gas supply subsystem 84 may fluidly connect the pressurized gassource 82 to the tire 58. The gas supply subsystem 84 may include one ormore conduits, such as a hose, tubing, pipe, or combinations thereof. InFIG. 1, a first conduit 90 and a second conduit 92 are shown. The firstconduit 90 may be fluidly connected to and may receive pressurized gasfrom the pressurized gas source 82. The second conduit 92 may supplypressurized gas to the tire 58. In at least one embodiment, the secondconduit 92 may extend through the hole in the fastener 72 or may beseparated into segments. For example, a first segment may extend fromthe rotary coupling 28 to the fastener 72 and a second segment mayextend from the fastener 72 to the wheel 56 and/or tire 58. In addition,one or more valves may be associated with or provided with a conduit toenable or disable the flow of the pressurized gas from the pressurizedgas source 82 to one or more tires 58. The routing of the conduitsbetween the pressurized gas source 82 and a tire 58 is exemplary and isnot meant to be limiting as other conduit routing paths may be provided.The flow of pressurized gas is represented by the arrows in the conduitsin FIG. 1.

Referring to FIGS. 2 and 3, exemplary rotary couplings are shown. Arotary coupling may facilitate routing of pressurized gas from thepressurized gas source 82 to the tire 58 while allowing the wheel endassembly 26 to rotate about the axis 30. For instance, the rotarycoupling may receive pressurized gas from the pressurized gas source 82via a first conduit 90 and may fluidly connect the first conduit 90 tothe second conduit 92. In at least one embodiment, the rotary couplingmay be disposed between the pressurized gas source 82 and the hub 50. Inaddition, the rotary coupling may be spaced apart from the wheel endassembly 26 and associated components, such as the hub 50 and wheel endseal assembly 52.

Referring to FIG. 2, a first embodiment of a rotary coupling 28 isshown. The rotary coupling 28 may include at least one mounting member100, a bracket 102, a rotating member 104, one or more seals 106, one ormore bearings 108, a tone ring sensor 110, and a tone ring 112.

The mounting member 100 may facilitate mounting of the rotary coupling28. For example, the mounting member 100 may be fixedly disposed on acomponent that may be stationary with respect to the axis 30, such asthe axle housing 20 and/or spindle 24. In the embodiment shown in FIG.2, the mounting member 100 is disposed on the axle housing 20 and mayextend radially or substantially perpendicular to the axis 30. Themounting member 100 may be attached to the axle housing 20 and/orspindle 24 in any suitable manner, such as by welding or with one ormore fasteners. The mounting member 100 may include a passage 120 and atone ring sensor hole 122.

The passage 120 may extend through the mounting member 100 to a chamber124 that may be disposed between the mounting member 100 and therotating member 104. In at least one embodiment, the chamber 124 may bedisposed between a pair of bearings 108 that may be disposed between themounting member 100 and the rotating member 104. The chamber 124 mayextend continuously around the axis 30 in a ring-like manner in one ormore embodiments.

The tone ring sensor hole 122 may be configured as a through hole thatmay extend through the mounting member 100. The tone ring sensor hole122 may be spaced apart from the passage 120 and may receive the tonering sensor 110.

The bracket 102 may position and hold the rotating member 104. Thebracket 102 may be fixedly disposed on the mounting member 100. As such,the bracket 102 may not rotate with the hub 50 and/or the rotatingmember 104 in one or more embodiments.

The bracket 102 may be provided in various configurations. In FIG. 2, abracket 102 is shown that may position and/or hold the rotating member104 against a pair of bearings 108 that may be disposed between themounting member 100 and the rotating member 104. As such, the bracket102 may hold the rotating member 104 against the bearings 108 such thatleakage of pressurized gas between the rotating member 104 and thebearings 108 is inhibited. A single bracket 102 may extend continuouslyaround the axis 30 in a ring-like manner or a plurality of brackets 102may be provided that may be spaced apart from each other and arrangedaround the axis 30 to hold the rotating member against the bearings 108.The bracket 102 may be secured to the mounting member 100 in anysuitable manner, such as by welding or with one or more fasteners.

The bracket 102 may include a gas passage opening 126. In FIG. 2, thegas passage opening 126 is configured as a through hole and extendsgenerally away from the axis 30. The gas passage opening 126 may receivepressurized gas from the rotating member 104 and permit pressurized gasto flow through the gas passage opening 126 to the second conduit 92.The gas passage opening 126 may be omitted in various embodiments, suchas when pressurized gas is routed through the rotating member 104,rather than through the rotating member 104 and the bracket 102.

The rotating member 104 may fluidly connect the chamber 124 to thesecond conduit 92. The rotating member 104 may be configured as a ringthat may extend continuously around the spindle 24 and the axis 30. Inat least one embodiment, the rotating member 104 may have a firstrotating member surface 130, a second rotating member surface 132, anouter rotating member surface 134, an inner rotating member surface 136,and a rotating member passage 138.

The first rotating member surface 130 may face away from the mountingmember 100. The first rotating member surface 130 may be disposedproximate a bearing 108 that may be disposed between the bracket 102 andthe rotating member 104.

The second rotating member surface 132 may face toward the mountingmember 100. The second rotating member surface 132 may be spaced apartfrom the mounting member 100 and may at least partially define thechamber 124. In addition, the tone ring 112 may be disposed proximatethe second rotating member surface 132. In FIG. 2, the tone ring 112 isdisposed in a groove in the second rotating member surface 132.

The outer rotating member surface 134 may extend from the first rotatingmember surface 130 to the second rotating member surface 132. The outerrotating member surface 134 may be spaced apart from the inner rotatingmember surface 136 and may at least partially define an outside surfaceor outside circumference of the rotating member 104. The outer rotatingmember surface 134 may be disposed proximate or may engage the bracket102 to help position the rotating member 104 and inhibit movement of therotating member 104 away from the axis 30.

The inner rotating member surface 136 may be disposed opposite the outerrotating member surface 134. The inner rotating member surface 136 mayface toward the axis 30 and may at least partially define an insidesurface or inside circumference of the rotating member 104. In theembodiment shown in FIG. 2, the inner rotating member surface 136 may bespaced apart from the axle housing 20 and/or spindle 24 to facilitaterotation of the rotating member 104 about the axis 30 and with respectto the axle housing 20 and/or spindle 24. As such, a gap 140 may bepresent between the axle housing 20 and the inner rotating membersurface 136.

The rotating member passage 138 may be configured as a through hole thatmay extend through the rotating member 104. In the embodiment shown inFIG. 2, the rotating member passage 138 extends from the second rotatingmember surface 132 to the outer rotating member surface 134.Alternatively, the rotating member passage 138 may extend through therotating member 104 in a different manner. For example, the rotatingmember passage 138 may extend from the first rotating member surface 130to the second rotating member surface 132. The rotating member passage138 may include a rotating member groove 142. The rotating member groove142 may be provided with the outer rotating member surface 134 and mayface toward the bracket 102. The rotating member groove 142 may extendcontinuously around the axis 30 in a ring-like manner. As such, therotating member groove 142 may distribute pressurized gas around theaxis 30 and permit pressurized gas to flow through an opening in themounting bracket 120 as the rotating member 104 rotates with respect tothe mounting member 100 and/or bracket 102. In addition, the rotatingmember groove 142 may allow for a continuous fluid connection betweenthe rotating member passage 138 and the second conduit 92 independent ofthe rotational position of the rotating member 104.

One or more seals 106 may be provided to inhibit leakage of pressurizedgas from the chamber 124. In the embodiment shown in FIG. 2, two seals106 are shown that are spaced apart from each other and disposed betweenthe bearings 108 that are provided between the mounting member 100 andthe rotating member 104. Alternatively, the position of a seal 106 and abearing 108 may be reversed such that the seal 106 may be disposedoutside a bearing 108. A seal 106 may extend around the axis 30 and fromthe mounting member 100 to the rotating member 104. In addition, theseal 106 may be spaced apart from a bearing 108 in one or moreembodiments. Optionally, seal functionality may be incorporated with oneor more bearings 108 in addition to or in place of a separate seal 106.

One or more bearings 108 may be provided to facilitate rotation of therotating member 104 with respect to the mounting member 100 and/orbracket 102. In the embodiment shown in FIG. 2, three bearings 108 areshown. More specifically, two bearings 108 are provided between themounting member 100 and the rotating member 104 and one bearing 108 isprovided between the rotating member 104 and the bracket 102. Thebearings 108 between the mounting member 100 and bracket 102 may atleast partially define the chamber 124 and may be configured to inhibitleakage of pressurized gas from the chamber 124. In addition, thebearings 108 may facilitate rotation of the rotating member 104 aboutthe axis 30. The third bearing 108, if provided, may be disposed betweenthe first rotating member surface 130 and the bracket 102 to helpinhibit axial movement of the rotating member 104, or movement of therotating member 104 in a direction that extends generally along orparallel to the axis 30.

The tone ring sensor 110 may be provided with an antilock brake systemand may be configured to detect rotation of the wheel end assembly 26about the axis 30. The tone ring sensor 110 may detect features that maybe provided with the tone ring 112. For instance, the tone ring 112 mayhave a plurality of openings that may be spaced apart from each other.The tone ring sensor 110 may detect the presence or absence of anopening in the tone ring 112 and may provide a corresponding signal thatmay be indicative of rotation of the hub 50 and wheel 56.

Referring to FIG. 3, another version of a rotary coupling 28′ is shown.The rotary coupling 28′ may include at least one mounting member 100′, ablock 102′, a rotating member 104′ and one or more seals 106′. Inaddition, the rotary coupling 28′ may include one or more bearings 108,a tone ring sensor 110, and a tone ring 112 as previously described.

The mounting member 100′ may facilitate mounting of the rotary coupling28′. In FIG. 3, two mounting members 100′ are shown that are spacedapart from each other. The mounting members 100′ may be fixedly disposedon a component that may be stationary with respect to the axis 30, suchas the axle housing 20 and/or spindle 24. For convenience in reference,the mounting member 100′ located to the left in FIG. 3, may be referredto as a first mounting member 100′ and the mounting member located tothe right in FIG. 3 may be referred to as a second mounting member 100′.The mounting member 100′ may be attached to the axle housing 20 and/orthe spindle 24 in any suitable manner, such as by welding or with one ormore fasteners. A mounting member 100′ may include a passage 120′ and atone ring sensor hole 122′. The passage 120′ may extend through themounting member 100′ to or toward the block 102′. The tone ring sensorhole 122′ may extend through a mounting member 100′ toward the rotatingmember 104′ and may receive the tone ring sensor 110.

A chamber 124′ may be disposed between the mounting members 100′. In atleast one embodiment, the chamber 124′ may be spaced apart from themounting members 100′ and disposed between a pair of bearings 108 thatmay be disposed proximate the mounting member 100′. The chamber 124′ mayalso be disposed between the block 102′ and the rotating member 104′.The chamber 124′ may extend continuously around the axis 30 in aring-like manner in one or more embodiments.

The block 102′ may be disposed proximate or adjacent to at least onemounting member 100′. In addition, the block 102′ may be disposedproximate or adjacent to a stationary component, such as the axlehousing 20 and/or the spindle 24. In at least one embodiment, the block102′ may be stationary or fixedly positioned with respect to the axlehousing 20, spindle 24, and/or mounting member 100′. The block 102′ mayinclude a block passage 128′. The block passage 128′ may extend throughthe block 102′ and may fluidly connect the passage 120′ to the chamber124′. In FIG. 3, the block passage 128′ has an inlet that is disposedadjacent to the passage 120′ and an outlet that is disposed between thebearings 108.

The rotating member 104′ may fluidly connect the chamber 124′ to thesecond conduit 92. The rotating member 104′ may be configured as a ringthat may extend continuously around the spindle 24, the axis 30, and/orthe block 102′. In at least one embodiment, the rotating member 104′ mayhave a first rotating member surface 130′, a second rotating membersurface 132′, an outer rotating member surface 134′, an inner rotatingmember surface 136′, and a rotating member passage 138′.

The first rotating member surface 130′ may face toward and may bedisposed proximate the first mounting member 100′. The second rotatingmember surface 132′ may face toward and may be disposed proximate thesecond mounting member 100′. The first and second mounting members 100′may cooperate with the first and second rotating member surfaces 130′,132′ and/or the seals 106′ to inhibit axial movement of the rotatingmember 104′. In addition, the tone ring 112 may be disposed proximatethe second rotating member surface 132′.

The outer rotating member surface 134′ may extend from the firstrotating member surface 130′ to the second rotating member surface 132′.The outer rotating member surface 134′ may be spaced apart from theinner rotating member surface 136′ and may at least partially define anoutside surface or outside circumference of the rotating member 104′.The outer rotating member surface 134′ may be disposed proximate or mayengage the second conduit 92.

The inner rotating member surface 136′ may be disposed opposite theouter rotating member surface 134′. The inner rotating member surface136′ may face toward the axis 30 and may at least partially define aninside surface or inside circumference of the rotating member 104′. Inthe embodiment shown in FIG. 3, the inner rotating member surface 136′may face toward and may engage the bearings 108 and may at leastpartially define a chamber 124′. The inner rotating member surface 136′may be spaced apart from the block 102′ to facilitate rotation of therotating member 104′ about the axis 30 and with respect to the axlehousing 20 and/or spindle 24.

The rotating member passage 138′ may be configured as a through holethat may extend through the rotating member 104′. In the embodimentshown in FIG. 3, the rotating member passage 138′ extends from the innerrotating member surface 136′ to the outer rotating member surface 134′.Alternatively, the rotating member passage 138′ may extend through therotating member 104′ in a different manner, such as out of the first orsecond rotating member surfaces 130′, 132′ in a location that is spacedapart from a mounting member 100′.

One or more seals 106′ may be provided to inhibit leakage of pressurizedgas from the chamber 124′. In the embodiment shown in FIG. 2, two seals106′ are shown that are spaced apart from each other and disposedbetween the mounting member 100′ and the rotating member 104′. A firstseal 106′ may engage and may be disposed between the first mountingmember 100′ and the rotating member 104′. A second seal 106′ may engageand may be disposed between the second mounting member 100′ and therotating member 104′. A seal 106′ may extend around the axis 30 and maybe spaced apart from a bearing 108 in one or more embodiments.Optionally, seal functionality may be incorporated with the rotatingmember 104′ through engagement with a mounting member 100′ or with oneor more bearings 108 in addition to or in place of a separate seal 106′.

One or more bearings 108 may be provided to facilitate rotation of therotating member 104′ with respect to the mounting member 100′ and/or theblock 102′. In the embodiment shown in FIG. 3, two bearings 108 areshown that are provided between the mounting members 100′ and betweenthe block 102′ and the rotating member 104′.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A tire inflation system comprising: a firstconduit for supplying a pressurized gas for inflating a tire; an axlehousing; a hub that is rotatably disposed on the axle housing; and arotary coupling that is axially spaced apart from the hub and includes:a mounting member that is disposed proximate the axle housing and thefirst conduit; a rotating member that is rotatably coupled to themounting member, wherein the rotating member has a rotating memberpassage that fluidly connects the first conduit to a second conduit thatis fluidly connected to the tire; and a mounting bracket that is fixedlydisposed on the mounting member and that radially extends around therotating member to help position the rotating member.
 2. The tireinflation system of claim 1 wherein the mounting member is fixedlydisposed on the axle housing.
 3. The tire inflation system of claim 1wherein the rotating member is spaced apart from the mounting membersuch that a chamber is formed between the mounting member and therotating member, wherein the chamber fluidly connects the first conduitto the rotating member passage.
 4. The tire inflation system of claim 3wherein the mounting member has a passage that fluidly connects thefirst conduit to the chamber.
 5. The tire inflation system of claim 1further comprising a bearing that is disposed between the mountingmember and the rotating member that facilitates rotation of the rotatingmember with respect to the mounting member.
 6. The tire inflation systemof claim 1 wherein the rotating member extends around and is spacedapart from the axle housing.
 7. The tire inflation system of claim 6wherein the rotating member has an inner rotating member surface thatfaces toward and is spaced apart from the axle housing.
 8. The tireinflation system of claim 1 wherein the rotating member includes arotating member groove that extends continuously around an axis and thatfluidly connects the rotating member passage to the second conduit. 9.The tire inflation system of claim 1 wherein the rotating member rotateswith respect to the mounting member.
 10. The tire inflation system ofclaim 9 wherein the mounting bracket has a gas passage opening thatconnects the rotating member passage to the second conduit.
 11. The tireinflation system of claim 9 further comprising a bearing that isdisposed between the mounting bracket and the rotating member.
 12. Thetire inflation system of claim 1 wherein the second conduit extendsthrough a wheel that supports the tire.
 13. A tire inflation systemcomprising: a first conduit for supplying a pressurized gas forinflating a tire; an axle housing; and a rotary coupling that includes:a mounting member that is disposed proximate the axle housing and thefirst conduit; a rotating member that rotates about an axis and isrotatably coupled to the mounting member, wherein the rotating memberhas a rotating member passage that fluidly connects the first conduit toa second conduit that is fluidly connected to the tire and a rotatingmember groove that extends continuously around the axis and is disposedon an outer rotating member surface that extends around the axis; and amounting bracket that is fixedly disposed on the mounting member andthat engages the outer rotating member surface.
 14. The tire inflationsystem of claim 13 wherein the rotating member groove faces toward themounting bracket and provides pressurized gas to the second conduit. 15.The tire inflation system of claim 13 wherein the rotary coupling isaxially spaced apart from and does not engage a wheel end assemblyhaving a hub that rotates about the axis and that supports a wheel thatsupports the tire.
 16. A tire inflation system comprising: a firstconduit for supplying a pressurized gas for inflating a tire; an axlehousing; and a rotary coupling that includes: a mounting member that isdisposed proximate the axle housing and the first conduit; a rotatingmember that is rotatably coupled to the mounting member, wherein therotating member has a rotating member passage that fluidly connects thefirst conduit to a second conduit that is fluidly connected to the tire;a mounting bracket that is fixedly disposed on the mounting member andthat radially extends around the rotating member to help position therotating member; and a pair of bearings that are disposed between themounting member and the rotating member, wherein the pair of bearingsfacilitates rotation of the rotating member with respect to the mountingmember.
 17. The tire inflation system of claim 16 wherein the pair ofbearings extends from the mounting member to the rotating member. 18.The tire inflation system of claim 16 further comprising a third bearingdisposed between the rotating member and the mounting bracket.
 19. Thetire inflation system of claim 18 wherein the third bearing extends fromthe rotating member to the mounting bracket.
 20. The tire inflationsystem of claim 16 wherein the rotary coupling is rotatable about anaxis and is axially spaced apart from and does not engage a wheel endassembly having a hub that rotates about the axis and that supports awheel that supports the tire.
 21. The tire inflation system of claim 16wherein the rotary coupling is rotatable about an axis and a pair ofseals extend around the axis and extend from the mounting member to therotating member such that the pair of seals is disposed between the pairof bearings.